// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_HTTP_HTTP_PROXY_CLIENT_SOCKET_H_
#define NET_HTTP_HTTP_PROXY_CLIENT_SOCKET_H_

#include <stdint.h>

#include <string>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "net/base/completion_callback.h"
#include "net/base/host_port_pair.h"
#include "net/base/load_timing_info.h"
#include "net/base/net_export.h"
#include "net/http/http_auth_controller.h"
#include "net/http/http_request_headers.h"
#include "net/http/http_request_info.h"
#include "net/http/http_response_info.h"
#include "net/http/proxy_client_socket.h"
#include "net/log/net_log.h"
#include "net/socket/ssl_client_socket.h"

namespace net {

class AddressList;
class ClientSocketHandle;
class GrowableIOBuffer;
class HttpStream;
class HttpStreamParser;
class IOBuffer;
class ProxyDelegate;

class NET_EXPORT_PRIVATE HttpProxyClientSocket : public ProxyClientSocket {
public:
    // Takes ownership of |transport_socket|, which should already be connected
    // by the time Connect() is called.  If tunnel is true then on Connect()
    // this socket will establish an Http tunnel.
    HttpProxyClientSocket(ClientSocketHandle* transport_socket,
        const std::string& user_agent,
        const HostPortPair& endpoint,
        const HostPortPair& proxy_server,
        HttpAuthController* http_auth_controller,
        bool tunnel,
        bool using_spdy,
        NextProto protocol_negotiated,
        ProxyDelegate* proxy_delegate,
        bool is_https_proxy);

    // On destruction Disconnect() is called.
    ~HttpProxyClientSocket() override;

    // ProxyClientSocket implementation.
    const HttpResponseInfo* GetConnectResponseInfo() const override;
    HttpStream* CreateConnectResponseStream() override;
    int RestartWithAuth(const CompletionCallback& callback) override;
    const scoped_refptr<HttpAuthController>& GetAuthController() const override;
    bool IsUsingSpdy() const override;
    NextProto GetProtocolNegotiated() const override;

    // StreamSocket implementation.
    int Connect(const CompletionCallback& callback) override;
    void Disconnect() override;
    bool IsConnected() const override;
    bool IsConnectedAndIdle() const override;
    const BoundNetLog& NetLog() const override;
    void SetSubresourceSpeculation() override;
    void SetOmniboxSpeculation() override;
    bool WasEverUsed() const override;
    bool WasNpnNegotiated() const override;
    NextProto GetNegotiatedProtocol() const override;
    bool GetSSLInfo(SSLInfo* ssl_info) override;
    void GetConnectionAttempts(ConnectionAttempts* out) const override;
    void ClearConnectionAttempts() override { }
    void AddConnectionAttempts(const ConnectionAttempts& attempts) override { }
    int64_t GetTotalReceivedBytes() const override;

    // Socket implementation.
    int Read(IOBuffer* buf,
        int buf_len,
        const CompletionCallback& callback) override;
    int Write(IOBuffer* buf,
        int buf_len,
        const CompletionCallback& callback) override;
    int SetReceiveBufferSize(int32_t size) override;
    int SetSendBufferSize(int32_t size) override;
    int GetPeerAddress(IPEndPoint* address) const override;
    int GetLocalAddress(IPEndPoint* address) const override;

private:
    enum State {
        STATE_NONE,
        STATE_GENERATE_AUTH_TOKEN,
        STATE_GENERATE_AUTH_TOKEN_COMPLETE,
        STATE_SEND_REQUEST,
        STATE_SEND_REQUEST_COMPLETE,
        STATE_READ_HEADERS,
        STATE_READ_HEADERS_COMPLETE,
        STATE_DRAIN_BODY,
        STATE_DRAIN_BODY_COMPLETE,
        STATE_DONE,
    };

    // The size in bytes of the buffer we use to drain the response body that
    // we want to throw away.  The response body is typically a small error
    // page just a few hundred bytes long.
    static const int kDrainBodyBufferSize = 1024;

    int PrepareForAuthRestart();
    int DidDrainBodyForAuthRestart();

    void LogBlockedTunnelResponse() const;

    void DoCallback(int result);
    void OnIOComplete(int result);

    int DoLoop(int last_io_result);
    int DoGenerateAuthToken();
    int DoGenerateAuthTokenComplete(int result);
    int DoSendRequest();
    int DoSendRequestComplete(int result);
    int DoReadHeaders();
    int DoReadHeadersComplete(int result);
    int DoDrainBody();
    int DoDrainBodyComplete(int result);

    CompletionCallback io_callback_;
    State next_state_;

    // Stores the callback to the layer above, called on completing Connect().
    CompletionCallback user_callback_;

    HttpRequestInfo request_;
    HttpResponseInfo response_;

    scoped_refptr<GrowableIOBuffer> parser_buf_;
    std::unique_ptr<HttpStreamParser> http_stream_parser_;
    scoped_refptr<IOBuffer> drain_buf_;

    // Stores the underlying socket.
    std::unique_ptr<ClientSocketHandle> transport_;

    // The hostname and port of the endpoint.  This is not necessarily the one
    // specified by the URL, due to Alternate-Protocol or fixed testing ports.
    const HostPortPair endpoint_;
    scoped_refptr<HttpAuthController> auth_;
    const bool tunnel_;
    // If true, then the connection to the proxy is a SPDY connection.
    const bool using_spdy_;
    // Protocol negotiated with the server.
    NextProto protocol_negotiated_;
    // If true, then SSL is used to communicate with this proxy
    const bool is_https_proxy_;

    std::string request_line_;
    HttpRequestHeaders request_headers_;

    // Used only for redirects.
    bool redirect_has_load_timing_info_;
    LoadTimingInfo redirect_load_timing_info_;

    const HostPortPair proxy_server_;

    // This delegate must outlive this proxy client socket.
    ProxyDelegate* proxy_delegate_;

    const BoundNetLog net_log_;

    DISALLOW_COPY_AND_ASSIGN(HttpProxyClientSocket);
};

} // namespace net

#endif // NET_HTTP_HTTP_PROXY_CLIENT_SOCKET_H_
